1. Field of the Invention
This invention relates generally to hand held portable power tools and, more particularly, to a battery powered, motor driven tool for pruning plant limbs, stems and the like.
2. Description of the Prior Art
U.S. Pat. No. 3,373,489 illustrates a pruning device which includes a motor, a saw blade, and a trigger type switch. The saw blade, which rotates about an axis perpendicular to the axis of the tool, includes recesses integral with the teeth for driving engagement with a pinion rotated by the motor. A pair of forwardly extending arms direct the branch of a tree to the saw blade. This device suffers from the disadvantage that the blade is continuously exposed in the area between the arms creating the possibility of injury to the user. Furthermore, since the device is trigger actuated, energy may be wasted since the motor may be energized prior to contact of the blade with the limb and continue to be energized after the limb has been cut.
U.S. Pat. No 2,274,421 teaches a pruning device having a motor, a trigger type switch and a blade. Power from the motor to the blade, which also rotates about an axis perpendicular to the axis of the tool, is transmitted through a pair of bevel gears. A pair of shields encloses the forward portion of the blade such that as the device is pushed against a branch, limb or stem, the shields separate in opposite directions exposing the blade. While the safety of this device has been enhanced due to the shield, energy may still be wasted since the motor may be energized prior to contact with the branch or limb and remain energized after the branch has been cut.
Additional cutting devices are described in U.S. Pat. Nos. 2,342,052 and 3,282,308.